1// SPDX-License-Identifier: GPL-2.0
2/*
3 * cacheinfo support - processor cache information via sysfs
4 *
5 * Based on arch/x86/kernel/cpu/intel_cacheinfo.c
6 * Author: Sudeep Holla <sudeep.holla@arm.com>
7 */
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/acpi.h>
11#include <linux/bitops.h>
12#include <linux/cacheinfo.h>
13#include <linux/compiler.h>
14#include <linux/cpu.h>
15#include <linux/device.h>
16#include <linux/init.h>
17#include <linux/of.h>
18#include <linux/sched.h>
19#include <linux/slab.h>
20#include <linux/smp.h>
21#include <linux/sysfs.h>
22
23/* pointer to per cpu cacheinfo */
24static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo);
25#define ci_cacheinfo(cpu) (&per_cpu(ci_cpu_cacheinfo, cpu))
26#define cache_leaves(cpu) (ci_cacheinfo(cpu)->num_leaves)
27#define per_cpu_cacheinfo(cpu) (ci_cacheinfo(cpu)->info_list)
28
29struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
30{
31 return ci_cacheinfo(cpu);
32}
33
34#ifdef CONFIG_OF
35static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
36 struct cacheinfo *sib_leaf)
37{
38 return sib_leaf->fw_token == this_leaf->fw_token;
39}
40
41/* OF properties to query for a given cache type */
42struct cache_type_info {
43 const char *size_prop;
44 const char *line_size_props[2];
45 const char *nr_sets_prop;
46};
47
48static const struct cache_type_info cache_type_info[] = {
49 {
50 .size_prop = "cache-size",
51 .line_size_props = { "cache-line-size",
52 "cache-block-size", },
53 .nr_sets_prop = "cache-sets",
54 }, {
55 .size_prop = "i-cache-size",
56 .line_size_props = { "i-cache-line-size",
57 "i-cache-block-size", },
58 .nr_sets_prop = "i-cache-sets",
59 }, {
60 .size_prop = "d-cache-size",
61 .line_size_props = { "d-cache-line-size",
62 "d-cache-block-size", },
63 .nr_sets_prop = "d-cache-sets",
64 },
65};
66
67static inline int get_cacheinfo_idx(enum cache_type type)
68{
69 if (type == CACHE_TYPE_UNIFIED)
70 return 0;
71 return type;
72}
73
74static void cache_size(struct cacheinfo *this_leaf, struct device_node *np)
75{
76 const char *propname;
77 int ct_idx;
78
79 ct_idx = get_cacheinfo_idx(this_leaf->type);
80 propname = cache_type_info[ct_idx].size_prop;
81
82 of_property_read_u32(np, propname, &this_leaf->size);
83}
84
85/* not cache_line_size() because that's a macro in include/linux/cache.h */
86static void cache_get_line_size(struct cacheinfo *this_leaf,
87 struct device_node *np)
88{
89 int i, lim, ct_idx;
90
91 ct_idx = get_cacheinfo_idx(this_leaf->type);
92 lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
93
94 for (i = 0; i < lim; i++) {
95 int ret;
96 u32 line_size;
97 const char *propname;
98
99 propname = cache_type_info[ct_idx].line_size_props[i];
100 ret = of_property_read_u32(np, propname, &line_size);
101 if (!ret) {
102 this_leaf->coherency_line_size = line_size;
103 break;
104 }
105 }
106}
107
108static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
109{
110 const char *propname;
111 int ct_idx;
112
113 ct_idx = get_cacheinfo_idx(this_leaf->type);
114 propname = cache_type_info[ct_idx].nr_sets_prop;
115
116 of_property_read_u32(np, propname, &this_leaf->number_of_sets);
117}
118
119static void cache_associativity(struct cacheinfo *this_leaf)
120{
121 unsigned int line_size = this_leaf->coherency_line_size;
122 unsigned int nr_sets = this_leaf->number_of_sets;
123 unsigned int size = this_leaf->size;
124
125 /*
126 * If the cache is fully associative, there is no need to
127 * check the other properties.
128 */
129 if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
130 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
131}
132
133static bool cache_node_is_unified(struct cacheinfo *this_leaf,
134 struct device_node *np)
135{
136 return of_property_read_bool(np, "cache-unified");
137}
138
139static void cache_of_set_props(struct cacheinfo *this_leaf,
140 struct device_node *np)
141{
142 /*
143 * init_cache_level must setup the cache level correctly
144 * overriding the architecturally specified levels, so
145 * if type is NONE at this stage, it should be unified
146 */
147 if (this_leaf->type == CACHE_TYPE_NOCACHE &&
148 cache_node_is_unified(this_leaf, np))
149 this_leaf->type = CACHE_TYPE_UNIFIED;
150 cache_size(this_leaf, np);
151 cache_get_line_size(this_leaf, np);
152 cache_nr_sets(this_leaf, np);
153 cache_associativity(this_leaf);
154}
155
156static int cache_setup_of_node(unsigned int cpu)
157{
158 struct device_node *np;
159 struct cacheinfo *this_leaf;
160 struct device *cpu_dev = get_cpu_device(cpu);
161 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
162 unsigned int index = 0;
163
164 /* skip if fw_token is already populated */
165 if (this_cpu_ci->info_list->fw_token) {
166 return 0;
167 }
168
169 if (!cpu_dev) {
170 pr_err("No cpu device for CPU %d\n", cpu);
171 return -ENODEV;
172 }
173 np = cpu_dev->of_node;
174 if (!np) {
175 pr_err("Failed to find cpu%d device node\n", cpu);
176 return -ENOENT;
177 }
178
179 while (index < cache_leaves(cpu)) {
180 this_leaf = this_cpu_ci->info_list + index;
181 if (this_leaf->level != 1)
182 np = of_find_next_cache_node(np);
183 else
184 np = of_node_get(np);/* cpu node itself */
185 if (!np)
186 break;
187 cache_of_set_props(this_leaf, np);
188 this_leaf->fw_token = np;
189 index++;
190 }
191
192 if (index != cache_leaves(cpu)) /* not all OF nodes populated */
193 return -ENOENT;
194
195 return 0;
196}
197#else
198static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
199static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
200 struct cacheinfo *sib_leaf)
201{
202 /*
203 * For non-DT/ACPI systems, assume unique level 1 caches, system-wide
204 * shared caches for all other levels. This will be used only if
205 * arch specific code has not populated shared_cpu_map
206 */
207 return !(this_leaf->level == 1);
208}
209#endif
210
211int __weak cache_setup_acpi(unsigned int cpu)
212{
213 return -ENOTSUPP;
214}
215
216static int cache_shared_cpu_map_setup(unsigned int cpu)
217{
218 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
219 struct cacheinfo *this_leaf, *sib_leaf;
220 unsigned int index;
221 int ret = 0;
222
223 if (this_cpu_ci->cpu_map_populated)
224 return 0;
225
226 if (of_have_populated_dt())
227 ret = cache_setup_of_node(cpu);
228 else if (!acpi_disabled)
229 ret = cache_setup_acpi(cpu);
230
231 if (ret)
232 return ret;
233
234 for (index = 0; index < cache_leaves(cpu); index++) {
235 unsigned int i;
236
237 this_leaf = this_cpu_ci->info_list + index;
238 /* skip if shared_cpu_map is already populated */
239 if (!cpumask_empty(&this_leaf->shared_cpu_map))
240 continue;
241
242 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
243 for_each_online_cpu(i) {
244 struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
245
246 if (i == cpu || !sib_cpu_ci->info_list)
247 continue;/* skip if itself or no cacheinfo */
248 sib_leaf = sib_cpu_ci->info_list + index;
249 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
250 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
251 cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
252 }
253 }
254 }
255
256 return 0;
257}
258
259static void cache_shared_cpu_map_remove(unsigned int cpu)
260{
261 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
262 struct cacheinfo *this_leaf, *sib_leaf;
263 unsigned int sibling, index;
264
265 for (index = 0; index < cache_leaves(cpu); index++) {
266 this_leaf = this_cpu_ci->info_list + index;
267 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
268 struct cpu_cacheinfo *sib_cpu_ci;
269
270 if (sibling == cpu) /* skip itself */
271 continue;
272
273 sib_cpu_ci = get_cpu_cacheinfo(sibling);
274 if (!sib_cpu_ci->info_list)
275 continue;
276
277 sib_leaf = sib_cpu_ci->info_list + index;
278 cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
279 cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
280 }
281 if (of_have_populated_dt())
282 of_node_put(this_leaf->fw_token);
283 }
284}
285
286static void free_cache_attributes(unsigned int cpu)
287{
288 if (!per_cpu_cacheinfo(cpu))
289 return;
290
291 cache_shared_cpu_map_remove(cpu);
292
293 kfree(per_cpu_cacheinfo(cpu));
294 per_cpu_cacheinfo(cpu) = NULL;
295}
296
297int __weak init_cache_level(unsigned int cpu)
298{
299 return -ENOENT;
300}
301
302int __weak populate_cache_leaves(unsigned int cpu)
303{
304 return -ENOENT;
305}
306
307static int detect_cache_attributes(unsigned int cpu)
308{
309 int ret;
310
311 if (init_cache_level(cpu) || !cache_leaves(cpu))
312 return -ENOENT;
313
314 per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
315 sizeof(struct cacheinfo), GFP_KERNEL);
316 if (per_cpu_cacheinfo(cpu) == NULL)
317 return -ENOMEM;
318
319 /*
320 * populate_cache_leaves() may completely setup the cache leaves and
321 * shared_cpu_map or it may leave it partially setup.
322 */
323 ret = populate_cache_leaves(cpu);
324 if (ret)
325 goto free_ci;
326 /*
327 * For systems using DT for cache hierarchy, fw_token
328 * and shared_cpu_map will be set up here only if they are
329 * not populated already
330 */
331 ret = cache_shared_cpu_map_setup(cpu);
332 if (ret) {
333 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
334 goto free_ci;
335 }
336
337 return 0;
338
339free_ci:
340 free_cache_attributes(cpu);
341 return ret;
342}
343
344/* pointer to cpuX/cache device */
345static DEFINE_PER_CPU(struct device *, ci_cache_dev);
346#define per_cpu_cache_dev(cpu) (per_cpu(ci_cache_dev, cpu))
347
348static cpumask_t cache_dev_map;
349
350/* pointer to array of devices for cpuX/cache/indexY */
351static DEFINE_PER_CPU(struct device **, ci_index_dev);
352#define per_cpu_index_dev(cpu) (per_cpu(ci_index_dev, cpu))
353#define per_cache_index_dev(cpu, idx) ((per_cpu_index_dev(cpu))[idx])
354
355#define show_one(file_name, object) \
356static ssize_t file_name##_show(struct device *dev, \
357 struct device_attribute *attr, char *buf) \
358{ \
359 struct cacheinfo *this_leaf = dev_get_drvdata(dev); \
360 return sprintf(buf, "%u\n", this_leaf->object); \
361}
362
363show_one(id, id);
364show_one(level, level);
365show_one(coherency_line_size, coherency_line_size);
366show_one(number_of_sets, number_of_sets);
367show_one(physical_line_partition, physical_line_partition);
368show_one(ways_of_associativity, ways_of_associativity);
369
370static ssize_t size_show(struct device *dev,
371 struct device_attribute *attr, char *buf)
372{
373 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
374
375 return sprintf(buf, "%uK\n", this_leaf->size >> 10);
376}
377
378static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
379{
380 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
381 const struct cpumask *mask = &this_leaf->shared_cpu_map;
382
383 return cpumap_print_to_pagebuf(list, buf, mask);
384}
385
386static ssize_t shared_cpu_map_show(struct device *dev,
387 struct device_attribute *attr, char *buf)
388{
389 return shared_cpumap_show_func(dev, false, buf);
390}
391
392static ssize_t shared_cpu_list_show(struct device *dev,
393 struct device_attribute *attr, char *buf)
394{
395 return shared_cpumap_show_func(dev, true, buf);
396}
397
398static ssize_t type_show(struct device *dev,
399 struct device_attribute *attr, char *buf)
400{
401 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
402
403 switch (this_leaf->type) {
404 case CACHE_TYPE_DATA:
405 return sprintf(buf, "Data\n");
406 case CACHE_TYPE_INST:
407 return sprintf(buf, "Instruction\n");
408 case CACHE_TYPE_UNIFIED:
409 return sprintf(buf, "Unified\n");
410 default:
411 return -EINVAL;
412 }
413}
414
415static ssize_t allocation_policy_show(struct device *dev,
416 struct device_attribute *attr, char *buf)
417{
418 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
419 unsigned int ci_attr = this_leaf->attributes;
420 int n = 0;
421
422 if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
423 n = sprintf(buf, "ReadWriteAllocate\n");
424 else if (ci_attr & CACHE_READ_ALLOCATE)
425 n = sprintf(buf, "ReadAllocate\n");
426 else if (ci_attr & CACHE_WRITE_ALLOCATE)
427 n = sprintf(buf, "WriteAllocate\n");
428 return n;
429}
430
431static ssize_t write_policy_show(struct device *dev,
432 struct device_attribute *attr, char *buf)
433{
434 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
435 unsigned int ci_attr = this_leaf->attributes;
436 int n = 0;
437
438 if (ci_attr & CACHE_WRITE_THROUGH)
439 n = sprintf(buf, "WriteThrough\n");
440 else if (ci_attr & CACHE_WRITE_BACK)
441 n = sprintf(buf, "WriteBack\n");
442 return n;
443}
444
445static DEVICE_ATTR_RO(id);
446static DEVICE_ATTR_RO(level);
447static DEVICE_ATTR_RO(type);
448static DEVICE_ATTR_RO(coherency_line_size);
449static DEVICE_ATTR_RO(ways_of_associativity);
450static DEVICE_ATTR_RO(number_of_sets);
451static DEVICE_ATTR_RO(size);
452static DEVICE_ATTR_RO(allocation_policy);
453static DEVICE_ATTR_RO(write_policy);
454static DEVICE_ATTR_RO(shared_cpu_map);
455static DEVICE_ATTR_RO(shared_cpu_list);
456static DEVICE_ATTR_RO(physical_line_partition);
457
458static struct attribute *cache_default_attrs[] = {
459 &dev_attr_id.attr,
460 &dev_attr_type.attr,
461 &dev_attr_level.attr,
462 &dev_attr_shared_cpu_map.attr,
463 &dev_attr_shared_cpu_list.attr,
464 &dev_attr_coherency_line_size.attr,
465 &dev_attr_ways_of_associativity.attr,
466 &dev_attr_number_of_sets.attr,
467 &dev_attr_size.attr,
468 &dev_attr_allocation_policy.attr,
469 &dev_attr_write_policy.attr,
470 &dev_attr_physical_line_partition.attr,
471 NULL
472};
473
474static umode_t
475cache_default_attrs_is_visible(struct kobject *kobj,
476 struct attribute *attr, int unused)
477{
478 struct device *dev = kobj_to_dev(kobj);
479 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
480 const struct cpumask *mask = &this_leaf->shared_cpu_map;
481 umode_t mode = attr->mode;
482
483 if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
484 return mode;
485 if ((attr == &dev_attr_type.attr) && this_leaf->type)
486 return mode;
487 if ((attr == &dev_attr_level.attr) && this_leaf->level)
488 return mode;
489 if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
490 return mode;
491 if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
492 return mode;
493 if ((attr == &dev_attr_coherency_line_size.attr) &&
494 this_leaf->coherency_line_size)
495 return mode;
496 if ((attr == &dev_attr_ways_of_associativity.attr) &&
497 this_leaf->size) /* allow 0 = full associativity */
498 return mode;
499 if ((attr == &dev_attr_number_of_sets.attr) &&
500 this_leaf->number_of_sets)
501 return mode;
502 if ((attr == &dev_attr_size.attr) && this_leaf->size)
503 return mode;
504 if ((attr == &dev_attr_write_policy.attr) &&
505 (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
506 return mode;
507 if ((attr == &dev_attr_allocation_policy.attr) &&
508 (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
509 return mode;
510 if ((attr == &dev_attr_physical_line_partition.attr) &&
511 this_leaf->physical_line_partition)
512 return mode;
513
514 return 0;
515}
516
517static const struct attribute_group cache_default_group = {
518 .attrs = cache_default_attrs,
519 .is_visible = cache_default_attrs_is_visible,
520};
521
522static const struct attribute_group *cache_default_groups[] = {
523 &cache_default_group,
524 NULL,
525};
526
527static const struct attribute_group *cache_private_groups[] = {
528 &cache_default_group,
529 NULL, /* Place holder for private group */
530 NULL,
531};
532
533const struct attribute_group *
534__weak cache_get_priv_group(struct cacheinfo *this_leaf)
535{
536 return NULL;
537}
538
539static const struct attribute_group **
540cache_get_attribute_groups(struct cacheinfo *this_leaf)
541{
542 const struct attribute_group *priv_group =
543 cache_get_priv_group(this_leaf);
544
545 if (!priv_group)
546 return cache_default_groups;
547
548 if (!cache_private_groups[1])
549 cache_private_groups[1] = priv_group;
550
551 return cache_private_groups;
552}
553
554/* Add/Remove cache interface for CPU device */
555static void cpu_cache_sysfs_exit(unsigned int cpu)
556{
557 int i;
558 struct device *ci_dev;
559
560 if (per_cpu_index_dev(cpu)) {
561 for (i = 0; i < cache_leaves(cpu); i++) {
562 ci_dev = per_cache_index_dev(cpu, i);
563 if (!ci_dev)
564 continue;
565 device_unregister(ci_dev);
566 }
567 kfree(per_cpu_index_dev(cpu));
568 per_cpu_index_dev(cpu) = NULL;
569 }
570 device_unregister(per_cpu_cache_dev(cpu));
571 per_cpu_cache_dev(cpu) = NULL;
572}
573
574static int cpu_cache_sysfs_init(unsigned int cpu)
575{
576 struct device *dev = get_cpu_device(cpu);
577
578 if (per_cpu_cacheinfo(cpu) == NULL)
579 return -ENOENT;
580
581 per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
582 if (IS_ERR(per_cpu_cache_dev(cpu)))
583 return PTR_ERR(per_cpu_cache_dev(cpu));
584
585 /* Allocate all required memory */
586 per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
587 sizeof(struct device *), GFP_KERNEL);
588 if (unlikely(per_cpu_index_dev(cpu) == NULL))
589 goto err_out;
590
591 return 0;
592
593err_out:
594 cpu_cache_sysfs_exit(cpu);
595 return -ENOMEM;
596}
597
598static int cache_add_dev(unsigned int cpu)
599{
600 unsigned int i;
601 int rc;
602 struct device *ci_dev, *parent;
603 struct cacheinfo *this_leaf;
604 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
605 const struct attribute_group **cache_groups;
606
607 rc = cpu_cache_sysfs_init(cpu);
608 if (unlikely(rc < 0))
609 return rc;
610
611 parent = per_cpu_cache_dev(cpu);
612 for (i = 0; i < cache_leaves(cpu); i++) {
613 this_leaf = this_cpu_ci->info_list + i;
614 if (this_leaf->disable_sysfs)
615 continue;
616 if (this_leaf->type == CACHE_TYPE_NOCACHE)
617 break;
618 cache_groups = cache_get_attribute_groups(this_leaf);
619 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
620 "index%1u", i);
621 if (IS_ERR(ci_dev)) {
622 rc = PTR_ERR(ci_dev);
623 goto err;
624 }
625 per_cache_index_dev(cpu, i) = ci_dev;
626 }
627 cpumask_set_cpu(cpu, &cache_dev_map);
628
629 return 0;
630err:
631 cpu_cache_sysfs_exit(cpu);
632 return rc;
633}
634
635static int cacheinfo_cpu_online(unsigned int cpu)
636{
637 int rc = detect_cache_attributes(cpu);
638
639 if (rc)
640 return rc;
641 rc = cache_add_dev(cpu);
642 if (rc)
643 free_cache_attributes(cpu);
644 return rc;
645}
646
647static int cacheinfo_cpu_pre_down(unsigned int cpu)
648{
649 if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
650 cpu_cache_sysfs_exit(cpu);
651
652 free_cache_attributes(cpu);
653 return 0;
654}
655
656static int __init cacheinfo_sysfs_init(void)
657{
658 return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online",
659 cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
660}
661device_initcall(cacheinfo_sysfs_init);
662